blob: d407992c1481b27248a3e1c31f7d8d35c72b8edb [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Anycast support for IPv6
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09003 * Linux INET6 implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * Authors:
6 * David L Stevens (dlstevens@us.ibm.com)
7 *
8 * based heavily on net/ipv6/mcast.c
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
Randy Dunlap4fc268d2006-01-11 12:17:47 -080016#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/module.h>
18#include <linux/errno.h>
19#include <linux/types.h>
20#include <linux/random.h>
21#include <linux/string.h>
22#include <linux/socket.h>
23#include <linux/sockios.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/net.h>
25#include <linux/in6.h>
26#include <linux/netdevice.h>
27#include <linux/if_arp.h>
28#include <linux/route.h>
29#include <linux/init.h>
30#include <linux/proc_fs.h>
31#include <linux/seq_file.h>
32
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020033#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <net/sock.h>
35#include <net/snmp.h>
36
37#include <net/ipv6.h>
38#include <net/protocol.h>
39#include <net/if_inet6.h>
40#include <net/ndisc.h>
41#include <net/addrconf.h>
42#include <net/ip6_route.h>
43
44#include <net/checksum.h>
45
46static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
47
48/* Big ac list lock for all the sockets */
49static DEFINE_RWLOCK(ipv6_sk_ac_lock);
50
51static int
52ip6_onlink(struct in6_addr *addr, struct net_device *dev)
53{
54 struct inet6_dev *idev;
55 struct inet6_ifaddr *ifa;
56 int onlink;
57
58 onlink = 0;
YOSHIFUJI Hideaki8814c4b2006-09-22 14:44:24 -070059 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 idev = __in6_dev_get(dev);
61 if (idev) {
62 read_lock_bh(&idev->lock);
63 for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
64 onlink = ipv6_prefix_equal(addr, &ifa->addr,
65 ifa->prefix_len);
66 if (onlink)
67 break;
68 }
69 read_unlock_bh(&idev->lock);
70 }
YOSHIFUJI Hideaki8814c4b2006-09-22 14:44:24 -070071 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return onlink;
73}
74
75/*
76 * socket join an anycast group
77 */
78
79int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
80{
81 struct ipv6_pinfo *np = inet6_sk(sk);
82 struct net_device *dev = NULL;
83 struct inet6_dev *idev;
84 struct ipv6_ac_socklist *pac;
85 int ishost = !ipv6_devconf.forwarding;
86 int err = 0;
87
88 if (!capable(CAP_NET_ADMIN))
89 return -EPERM;
90 if (ipv6_addr_is_multicast(addr))
91 return -EINVAL;
92 if (ipv6_chk_addr(addr, NULL, 0))
93 return -EINVAL;
94
95 pac = sock_kmalloc(sk, sizeof(struct ipv6_ac_socklist), GFP_KERNEL);
96 if (pac == NULL)
97 return -ENOMEM;
98 pac->acl_next = NULL;
99 ipv6_addr_copy(&pac->acl_addr, addr);
100
101 if (ifindex == 0) {
102 struct rt6_info *rt;
103
104 rt = rt6_lookup(addr, NULL, 0, 0);
105 if (rt) {
106 dev = rt->rt6i_dev;
107 dev_hold(dev);
108 dst_release(&rt->u.dst);
109 } else if (ishost) {
110 err = -EADDRNOTAVAIL;
111 goto out_free_pac;
112 } else {
113 /* router, no matching interface: just pick one */
114
Eric W. Biederman881d9662007-09-17 11:56:21 -0700115 dev = dev_get_by_flags(&init_net, IFF_UP, IFF_UP|IFF_LOOPBACK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 }
117 } else
Eric W. Biederman881d9662007-09-17 11:56:21 -0700118 dev = dev_get_by_index(&init_net, ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
120 if (dev == NULL) {
121 err = -ENODEV;
122 goto out_free_pac;
123 }
124
125 idev = in6_dev_get(dev);
126 if (!idev) {
127 if (ifindex)
128 err = -ENODEV;
129 else
130 err = -EADDRNOTAVAIL;
131 goto out_dev_put;
132 }
133 /* reset ishost, now that we have a specific device */
134 ishost = !idev->cnf.forwarding;
135 in6_dev_put(idev);
136
137 pac->acl_ifindex = dev->ifindex;
138
139 /* XXX
140 * For hosts, allow link-local or matching prefix anycasts.
141 * This obviates the need for propagating anycast routes while
142 * still allowing some non-router anycast participation.
143 */
144 if (!ip6_onlink(addr, dev)) {
145 if (ishost)
146 err = -EADDRNOTAVAIL;
147 if (err)
148 goto out_dev_put;
149 }
150
151 err = ipv6_dev_ac_inc(dev, addr);
152 if (err)
153 goto out_dev_put;
154
155 write_lock_bh(&ipv6_sk_ac_lock);
156 pac->acl_next = np->ipv6_ac_list;
157 np->ipv6_ac_list = pac;
158 write_unlock_bh(&ipv6_sk_ac_lock);
159
160 dev_put(dev);
161
162 return 0;
163
164out_dev_put:
165 dev_put(dev);
166out_free_pac:
167 sock_kfree_s(sk, pac, sizeof(*pac));
168 return err;
169}
170
171/*
172 * socket leave an anycast group
173 */
174int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
175{
176 struct ipv6_pinfo *np = inet6_sk(sk);
177 struct net_device *dev;
178 struct ipv6_ac_socklist *pac, *prev_pac;
179
180 write_lock_bh(&ipv6_sk_ac_lock);
181 prev_pac = NULL;
182 for (pac = np->ipv6_ac_list; pac; pac = pac->acl_next) {
183 if ((ifindex == 0 || pac->acl_ifindex == ifindex) &&
184 ipv6_addr_equal(&pac->acl_addr, addr))
185 break;
186 prev_pac = pac;
187 }
188 if (!pac) {
189 write_unlock_bh(&ipv6_sk_ac_lock);
190 return -ENOENT;
191 }
192 if (prev_pac)
193 prev_pac->acl_next = pac->acl_next;
194 else
195 np->ipv6_ac_list = pac->acl_next;
196
197 write_unlock_bh(&ipv6_sk_ac_lock);
198
Eric W. Biederman881d9662007-09-17 11:56:21 -0700199 dev = dev_get_by_index(&init_net, pac->acl_ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 if (dev) {
201 ipv6_dev_ac_dec(dev, &pac->acl_addr);
202 dev_put(dev);
203 }
204 sock_kfree_s(sk, pac, sizeof(*pac));
205 return 0;
206}
207
208void ipv6_sock_ac_close(struct sock *sk)
209{
210 struct ipv6_pinfo *np = inet6_sk(sk);
211 struct net_device *dev = NULL;
212 struct ipv6_ac_socklist *pac;
213 int prev_index;
214
215 write_lock_bh(&ipv6_sk_ac_lock);
216 pac = np->ipv6_ac_list;
217 np->ipv6_ac_list = NULL;
218 write_unlock_bh(&ipv6_sk_ac_lock);
219
220 prev_index = 0;
221 while (pac) {
222 struct ipv6_ac_socklist *next = pac->acl_next;
223
224 if (pac->acl_ifindex != prev_index) {
225 if (dev)
226 dev_put(dev);
Eric W. Biederman881d9662007-09-17 11:56:21 -0700227 dev = dev_get_by_index(&init_net, pac->acl_ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 prev_index = pac->acl_ifindex;
229 }
230 if (dev)
231 ipv6_dev_ac_dec(dev, &pac->acl_addr);
232 sock_kfree_s(sk, pac, sizeof(*pac));
233 pac = next;
234 }
235 if (dev)
236 dev_put(dev);
237}
238
239#if 0
240/* The function is not used, which is funny. Apparently, author
241 * supposed to use it to filter out datagrams inside udp/raw but forgot.
242 *
243 * It is OK, anycasts are not special comparing to delivery to unicasts.
244 */
245
246int inet6_ac_check(struct sock *sk, struct in6_addr *addr, int ifindex)
247{
248 struct ipv6_ac_socklist *pac;
249 struct ipv6_pinfo *np = inet6_sk(sk);
250 int found;
251
252 found = 0;
253 read_lock(&ipv6_sk_ac_lock);
254 for (pac=np->ipv6_ac_list; pac; pac=pac->acl_next) {
255 if (ifindex && pac->acl_ifindex != ifindex)
256 continue;
257 found = ipv6_addr_equal(&pac->acl_addr, addr);
258 if (found)
259 break;
260 }
261 read_unlock(&ipv6_sk_ac_lock);
262
263 return found;
264}
265
266#endif
267
268static void aca_put(struct ifacaddr6 *ac)
269{
270 if (atomic_dec_and_test(&ac->aca_refcnt)) {
271 in6_dev_put(ac->aca_idev);
272 dst_release(&ac->aca_rt->u.dst);
273 kfree(ac);
274 }
275}
276
277/*
278 * device anycast group inc (add if not found)
279 */
280int ipv6_dev_ac_inc(struct net_device *dev, struct in6_addr *addr)
281{
282 struct ifacaddr6 *aca;
283 struct inet6_dev *idev;
284 struct rt6_info *rt;
285 int err;
286
287 idev = in6_dev_get(dev);
288
289 if (idev == NULL)
290 return -EINVAL;
291
292 write_lock_bh(&idev->lock);
293 if (idev->dead) {
294 err = -ENODEV;
295 goto out;
296 }
297
298 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
299 if (ipv6_addr_equal(&aca->aca_addr, addr)) {
300 aca->aca_users++;
301 err = 0;
302 goto out;
303 }
304 }
305
306 /*
307 * not found: create a new one.
308 */
309
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800310 aca = kzalloc(sizeof(struct ifacaddr6), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311
312 if (aca == NULL) {
313 err = -ENOMEM;
314 goto out;
315 }
316
317 rt = addrconf_dst_alloc(idev, addr, 1);
318 if (IS_ERR(rt)) {
319 kfree(aca);
320 err = PTR_ERR(rt);
321 goto out;
322 }
323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 ipv6_addr_copy(&aca->aca_addr, addr);
325 aca->aca_idev = idev;
326 aca->aca_rt = rt;
327 aca->aca_users = 1;
328 /* aca_tstamp should be updated upon changes */
329 aca->aca_cstamp = aca->aca_tstamp = jiffies;
330 atomic_set(&aca->aca_refcnt, 2);
331 spin_lock_init(&aca->aca_lock);
332
333 aca->aca_next = idev->ac_list;
334 idev->ac_list = aca;
335 write_unlock_bh(&idev->lock);
336
337 dst_hold(&rt->u.dst);
Thomas Graf40e22e82006-08-22 00:00:45 -0700338 if (ip6_ins_rt(rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 dst_release(&rt->u.dst);
340
341 addrconf_join_solict(dev, &aca->aca_addr);
342
343 aca_put(aca);
344 return 0;
345out:
346 write_unlock_bh(&idev->lock);
347 in6_dev_put(idev);
348 return err;
349}
350
351/*
352 * device anycast group decrement
353 */
354int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr)
355{
356 struct ifacaddr6 *aca, *prev_aca;
357
358 write_lock_bh(&idev->lock);
359 prev_aca = NULL;
360 for (aca = idev->ac_list; aca; aca = aca->aca_next) {
361 if (ipv6_addr_equal(&aca->aca_addr, addr))
362 break;
363 prev_aca = aca;
364 }
365 if (!aca) {
366 write_unlock_bh(&idev->lock);
367 return -ENOENT;
368 }
369 if (--aca->aca_users > 0) {
370 write_unlock_bh(&idev->lock);
371 return 0;
372 }
373 if (prev_aca)
374 prev_aca->aca_next = aca->aca_next;
375 else
376 idev->ac_list = aca->aca_next;
377 write_unlock_bh(&idev->lock);
378 addrconf_leave_solict(idev, &aca->aca_addr);
379
380 dst_hold(&aca->aca_rt->u.dst);
David S. Miller72d3b2c2006-08-22 00:13:07 -0700381 if (ip6_del_rt(aca->aca_rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 dst_free(&aca->aca_rt->u.dst);
383 else
384 dst_release(&aca->aca_rt->u.dst);
385
386 aca_put(aca);
387 return 0;
388}
389
390static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr)
391{
392 int ret;
393 struct inet6_dev *idev = in6_dev_get(dev);
394 if (idev == NULL)
395 return -ENODEV;
396 ret = __ipv6_dev_ac_dec(idev, addr);
397 in6_dev_put(idev);
398 return ret;
399}
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900400
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401/*
402 * check if the interface has this anycast address
403 */
404static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
405{
406 struct inet6_dev *idev;
407 struct ifacaddr6 *aca;
408
409 idev = in6_dev_get(dev);
410 if (idev) {
411 read_lock_bh(&idev->lock);
412 for (aca = idev->ac_list; aca; aca = aca->aca_next)
413 if (ipv6_addr_equal(&aca->aca_addr, addr))
414 break;
415 read_unlock_bh(&idev->lock);
416 in6_dev_put(idev);
417 return aca != 0;
418 }
419 return 0;
420}
421
422/*
423 * check if given interface (or any, if dev==0) has this anycast address
424 */
425int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
426{
Pavel Emelianov7562f872007-05-03 15:13:45 -0700427 int found = 0;
428
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 if (dev)
430 return ipv6_chk_acast_dev(dev, addr);
431 read_lock(&dev_base_lock);
Eric W. Biederman881d9662007-09-17 11:56:21 -0700432 for_each_netdev(&init_net, dev)
Pavel Emelianov7562f872007-05-03 15:13:45 -0700433 if (ipv6_chk_acast_dev(dev, addr)) {
434 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 break;
Pavel Emelianov7562f872007-05-03 15:13:45 -0700436 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 read_unlock(&dev_base_lock);
Pavel Emelianov7562f872007-05-03 15:13:45 -0700438 return found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439}
440
441
442#ifdef CONFIG_PROC_FS
443struct ac6_iter_state {
444 struct net_device *dev;
445 struct inet6_dev *idev;
446};
447
448#define ac6_seq_private(seq) ((struct ac6_iter_state *)(seq)->private)
449
450static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
451{
452 struct ifacaddr6 *im = NULL;
453 struct ac6_iter_state *state = ac6_seq_private(seq);
454
Pavel Emelianov7562f872007-05-03 15:13:45 -0700455 state->idev = NULL;
Eric W. Biederman881d9662007-09-17 11:56:21 -0700456 for_each_netdev(&init_net, state->dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 struct inet6_dev *idev;
458 idev = in6_dev_get(state->dev);
459 if (!idev)
460 continue;
461 read_lock_bh(&idev->lock);
462 im = idev->ac_list;
463 if (im) {
464 state->idev = idev;
465 break;
466 }
467 read_unlock_bh(&idev->lock);
David Stevensaa6e4a92007-02-26 16:28:56 -0800468 in6_dev_put(idev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 }
470 return im;
471}
472
473static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im)
474{
475 struct ac6_iter_state *state = ac6_seq_private(seq);
476
477 im = im->aca_next;
478 while (!im) {
479 if (likely(state->idev != NULL)) {
480 read_unlock_bh(&state->idev->lock);
481 in6_dev_put(state->idev);
482 }
Pavel Emelianov7562f872007-05-03 15:13:45 -0700483 state->dev = next_net_device(state->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 if (!state->dev) {
485 state->idev = NULL;
486 break;
487 }
488 state->idev = in6_dev_get(state->dev);
489 if (!state->idev)
490 continue;
491 read_lock_bh(&state->idev->lock);
492 im = state->idev->ac_list;
493 }
494 return im;
495}
496
497static struct ifacaddr6 *ac6_get_idx(struct seq_file *seq, loff_t pos)
498{
499 struct ifacaddr6 *im = ac6_get_first(seq);
500 if (im)
501 while (pos && (im = ac6_get_next(seq, im)) != NULL)
502 --pos;
503 return pos ? NULL : im;
504}
505
506static void *ac6_seq_start(struct seq_file *seq, loff_t *pos)
507{
508 read_lock(&dev_base_lock);
509 return ac6_get_idx(seq, *pos);
510}
511
512static void *ac6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
513{
514 struct ifacaddr6 *im;
515 im = ac6_get_next(seq, v);
516 ++*pos;
517 return im;
518}
519
520static void ac6_seq_stop(struct seq_file *seq, void *v)
521{
522 struct ac6_iter_state *state = ac6_seq_private(seq);
523 if (likely(state->idev != NULL)) {
524 read_unlock_bh(&state->idev->lock);
525 in6_dev_put(state->idev);
526 }
527 read_unlock(&dev_base_lock);
528}
529
530static int ac6_seq_show(struct seq_file *seq, void *v)
531{
532 struct ifacaddr6 *im = (struct ifacaddr6 *)v;
533 struct ac6_iter_state *state = ac6_seq_private(seq);
534
535 seq_printf(seq,
YOSHIFUJI Hideaki9343e792006-01-17 02:10:53 -0800536 "%-4d %-15s " NIP6_SEQFMT " %5d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 state->dev->ifindex, state->dev->name,
538 NIP6(im->aca_addr),
539 im->aca_users);
540 return 0;
541}
542
Philippe De Muyter56b3d972007-07-10 23:07:31 -0700543static const struct seq_operations ac6_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 .start = ac6_seq_start,
545 .next = ac6_seq_next,
546 .stop = ac6_seq_stop,
547 .show = ac6_seq_show,
548};
549
550static int ac6_seq_open(struct inode *inode, struct file *file)
551{
552 struct seq_file *seq;
553 int rc = -ENOMEM;
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800554 struct ac6_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555
556 if (!s)
557 goto out;
558
559 rc = seq_open(file, &ac6_seq_ops);
560 if (rc)
561 goto out_kfree;
562
563 seq = file->private_data;
564 seq->private = s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565out:
566 return rc;
567out_kfree:
568 kfree(s);
569 goto out;
570}
571
Arjan van de Ven9a321442007-02-12 00:55:35 -0800572static const struct file_operations ac6_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 .owner = THIS_MODULE,
574 .open = ac6_seq_open,
575 .read = seq_read,
576 .llseek = seq_lseek,
577 .release = seq_release_private,
578};
579
580int __init ac6_proc_init(void)
581{
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200582 if (!proc_net_fops_create(&init_net, "anycast6", S_IRUGO, &ac6_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 return -ENOMEM;
584
585 return 0;
586}
587
588void ac6_proc_exit(void)
589{
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200590 proc_net_remove(&init_net, "anycast6");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591}
592#endif
593